Process and apparatus for producing sheet glass



D 1930- o. c. MILLER 1,787,391

PROCESS AND APPARATUS FOR PRODUCING SHEET GLASS Filed Sept. 2. 1927 Otto C. Mil/er Patented Dec. 30, 1930 UNITED STATES PATIENT OFFICE OTTO C. MILLER, OF CHARLESTON, WEST VIRGINIA, ASSIGNOR TO LIBBEY-OWENS- FORD GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO PROCESS AND APPARATUS FOR PRODUCING SHEET GLASS Application filed September 2, 1927. Serial No. 217,082.

The present invention relates 'to an improved process and apparatus for producing sheet glass.

An important object of the invention is to provide in sheet glass apparatus, a pair of rolls arranged above a mass of molten glass, said rolls being rotated in a manner that the peripheral speed of one of said rolls is relatively greater than the peripheral speed of the other.

Another object of the invention is to provide in sheet glass apparatus, a mass of molten glass and a pair of positively driven rolls arranged thereabove and so mounted as to create a sheet forming pass therebetween, whereby molten glass may be moved vertically and then passed through said pass and reduced to a uniform thickness of sheet which is then deflected over one of said rolls, the peripheral speed of the roll over which the sheet is deflected being relatively slower than the peripheral speed of the other roll.

Still another object of the invention is to provide in an apparatus of this nature, a receptable containing a mass of molten glass,

a pair of positively driven rolls mounted thereabove and arranged to create a sheet forming pass, whereby upon proper handling of the molten glass and rotation of the rolls,

, a relatively heavy mass of glass is moved upwardly and through the forming pass to roll the same into a sheet having a predetermined thickness, the diameter of the roll over which the sheet is deflected being less than that of the other roll to equalize the speed of the sheet surfaces, while both of said rolls are driven at the same speed in revolutions per minute.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings wherein like numerals are employed to designate like parts throughout the same,

Fig. 1 is a fragmentary vertical longitudinal section through a machine illustrating .my improved construction in use,

50 t Fig. 2 is a similar view,

tion of Drake and Mambourg, Serial No.

214,278, filed August 20, 1927.

The numeral 5 designates a working receptacle or draw pot adapted to contain a mass of properly conditioned molten glass 6 which may be continuously furnished from any desired type of melting furnace 7. A1 ranged above the surface of the molten glass 6 is a pair of rolls 8 and 9 respectively. The rolls 8 and 9 are positioned in a manner to create a sheet forming pass, which pass determines the exact thickness of sheet produced. The rolls are preferably positively driven and in such a manner that a relatively thick heavy body of glass 10 is moved upwardly from the mass 6 so that the mass 10 may be actually rolled between the rolls to a flat sheet having a predetermined thickness. The sheet is designated by the numeral 11, and is adapted to be deflected into a horizontal plane over the roll 8, said sheet being supported and conveyed by means of the rolls or other means 12 shown in Fig. 1. Supplementary members 13 may be provided to prevent buckling or warping of the sheet after it has been formed, but are preferably such that there is no tendency toward a reduction in thickness of the sheet. By accurately determining the thickness of the sheet by the space between the rolls 8 and 9, it is possible to continuously produce a flat uniform sheet of predetermined thickness, which of course is desirable. To protect the rolls 8 and 9 and the mass of molten glass 10, as well as the sheet 11, from undesirable heat, the tiles 14 and 15 respec tively may be used, while the shields 16 and 17 may be used as shown.

It is preferable that the rolls be mounted above the molten glass in a manner that a straight line through their axes will be substantially horizontal so that the rolls, when in operative position, will assume substantially the position illustrated in the drawings.

When rolling a sheet with this apparatus, it will be seen that the lower surface of the sheet, or that surface contacting with the roll 8, does not have to move as great a distance as the outer surface or that surface contacting with the roll 9. If the peripheralspeeds of the two rolls are identical, the sheet will not be treated the same on both sides because of the differences in speed just mentioned. It is therefore an important object of the invention to so move the outer surface of the sheet that there will be no trouble resulting from this variation in'speed'of the two surfaces which results when the sheet is-deflected as illustrated. Therefore, to overcome these objections, the peripheral speeds ofthe rolls 8 and 9, in accordance with this invention, are different. This may be accomplished in one of two Ways which will hereinafter be described.

In Fig. 1, the diameter of the roll 8 is slightly less than the diameter of the roll 9, while at the same time the rolls are adapted to be driven at the same speed in revolutions per minute. By driving the rolls at the same speed and by constructing them in such a manner that their peripheral speeds are.dif ferent, and as the smaller roll 8 is positioned as shown, it will be seen that the outside surface of the sheet contacting with the roll 9 will move slightly faster than the inside surface. Thus, due to the different peripheral speed of the rolls, the movement of the surfaces of the sheet will be equalized by causing the outer surface to move relatively faster than the inner surface. Of course this difference in speed applies to the sheet only while it is being formed and deflected because when it reaches the horizontal there is no longer the necessity for a difference in speed of the two surfaces of the sheet. To prevent sagging of the sheet, the speed of the rollslQ may be such thatthe sheet will be placed under a slight tension, but thistension is suf ficient only to prevent sagging and not capable of causing any appreciable reduction in thickness.

In Fig. 3 is illustrated a different method of equalizing the movement of the sheet. As shown, a mass 18 is moved vertically from the source 19. Carried by the ends of the rolls 20 and 21,shown in Fig. 4, are the sprockets 22 and 23 driven by means of a sprocket chain 24. An idler 25 is used to take up slack in the chain 24 as will be readily understood. Each of the rolls is supported in a bracket 26 carried by an adjustable frame 27, which in turn is'carried by a support 28. The roll 20 is preferably mounted in a fixedbracket 26, while the other roll is preferably pivotally mounted on the bracket 2? to permit adjustment with respect to the stationary roll in a manner that the size of the sheet forming pass may be controlled as desired. To make the peripheral speed of the rolls different in the construction shown in Figs. 3 and 4, thediameters of the rolls are the same, but the roll 22 rolls in a mannerthat their peripheral speeds will be different. The temperature of the rolls is controlled bypassing a suitable medium therethrough.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape,

size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoine'd claims.

Claims:

1. In sheet glass apparatus, a receptacle containing a mass of molten glass, a pair of rolls disposed thereabove and arranged to create a sheet forming pass, and means for rotating the rolls in a manner to advance glass upwardly and through the pass to roll the glass into a sheet of predetermined thickness, the sheet being deflected over one of said rolls, the peripheral speed of theroll over which the sheet is deflected being relat-ively less than the peripheral speed of the other roll. I

2. In sheet glass apparatus, a receptacle containing a mass of molten glass, a pair of rolls disposed thereabove and arranged to create a sheet formingpass, means for rotating the rolls in a manner to advance glass upinto a sheet of predetermined thickness, the sheet being deflected over one of said'rolls,

the peripheral speed of the roll over which the sheet is deflected beingrelatively less than the peripheral speed of the other roll. and means for controlling the temperature of said rolls. 7 I

3.In sheet .glassapparatus, a receptacle containing a mass of molten glass, a pair of rolls disposed thereabove and arranged to create a sheet forming pass, means for rotating the rolls in a manner to, advance glass upwardly and through the pass to roll the glass into a sheet of predetermined thickness, the sheet being deflected'over one of said rolls, the peripheral speed of the. roll over which the sheet is deflected being relatively less than the peripheral speed of theother roll,

and me ans for placing the sheet under tension to prevent sagging thereof; r l i 7 l. In sheet glass apparatus, a receptacle containing a mass of molten glass, a pair of rolls disposed thereabove and arranged to wardly and through the pass to'roll the glass create a sheet forming pass, and means for rotating the rolls in a manner to advance glass upwardly and through the pass to roll the glass into a sheet of predetermined thickness, the sheet being deflected over one of said rolls, the peripheral speed of the roll over which the sheet is deflected being relatively less than the peripheral speed of the other roll, so that the outer surface of the sheet will move relatively faster than the inner surface of the sheet when said sheet is being deflected.

5. In sheet glass apparatus, a receptacle containing a mass of molten glass, a pair of rolls mounted therealoove and arranged to create a sheet forming pass, and means for driving said rolls at different relative speeds and in a manner to move glass upwardly and through the pass, said sheet being deflected over the slower moving roll.

6. In sheet glass apparatus, a receptacle containing a mass of molten glass, a pair of rolls mounted thereabove and arranged to create a sheet forming pass, and means for driving said rolls at different relative speeds and in a manner to move glass upwardly and through the pass, said sheet being deflected over the slower moving roll, the diameters of the rolls being the same so that the roll over which the sheet is deflected will have a relatively slower peripheral speed than that of the other roll.

7. The process of producing sheet glass, consisting in moving molten glass upwardly, deflecting the sheet into another plane, and positively moving the outer surface of the sheet relatively faster than the inner surface thereof.

Signed at Charleston, in the county of Kanawha and State of WVest Virginia, this twenty-ninth day of August, 1927.

OTTO C. MILLER. 

